When you want to search for aromatase inhibitors you first search for the Subject Heading mapping to aromatase inhibitors (aromatase inhibitor). Next you explode aromatase inhibitor/ if you are interested in all its narrower terms. If not, you search both for the general term aromatase inhibitor and those specific narrower terms you want to include.
Exploding aromatase inhibitor (exp aromatase inhibitor/) yields 15938 results. That is approximately twice what you get by searching aromatase inhibitor/ alone (not exploded). This yields 7434 hits.

It is different in MEDLINE. If you search for aromatase inhibitors in the MeSH database you get two suggestions.

The first index term “Aromatase Inhibitors” is a Mesh. It has no narrower terms.Drug-Mesh are generally not arranged by working mechanism, but by chemical structure/type of compound. That is often confusing. Spironolactone for instance belongs to the MeSH Lactones (and Pregnenes) not to the MeSH Aldosterone Antagonists or Androgen Antagonist. Most Clinicians want to search for a group of compounds with the same mechanism of action, not the same biochemical family

The second term “Aromatase Inhibitors” [Pharmacological Action] however does stand for the working mechanism.It does have narrower terms, including 2 MeSH terms (highlighted) and various substance names, also called Supplementary Concepts.

For complete results you have to search for both MeSH and Pharmacological action: “Aromatase Inhibitors”[Mesh] yields 3930 records, whereas (“Aromatase Inhibitors”[Mesh]) OR “Aromatase Inhibitors” [Pharmacological Action] yields 6045. That is a lot more.

I usually don’t search PubMed, but OVID MEDLINE.

I know that Pharmacological Action-subheadings are important, so I tried to find the equivalent in OVID .

I found the MeSH Aromatase Inhibitors, but -unlike PubMed- OVID showed only two narrower Drug Terms (called Non-MeSH here versus MeSH in PubMed).

I found that odd.

I reasoned “Pharmacological action” might perhaps be combined with the MESH in OVID MEDLINE. This was later confirmed by Melissa Rethlefsen (see Twitter discussion below)

In Ovid MEDLINE I got 3937 hits with Aromatase Inhibitors/ and 5219 with exp Aromatase Inhibitors/ (thus including aminogluthemide or Fadrozole)

At this point I checked PubMed (shown above). Here I found that “Aromatase Inhibitors”[Mesh] OR “Aromatase Inhibitors” [Pharmacological Action] yielded 6045 hits in PubMed, against 5219 in OVID MEDLINE for exp Aromatase Inhibitors/

But what explained the gap of approximately 800 records between “Aromatase Inhibitors”[Mesh] OR “Aromatase Inhibitors”[Pharmacological Action]* in PubMed and exp aromatase inhibitors/ in OVID MEDLINE?

Could it be the substance names, mentioned under “Aromatase Inhibitors”[Pharmacological Action], I wondered?

Thus I added all the individual substance names in OVID MEDLINE (code= .rn.). See search set 61 below.

Indeed these accounted fully for the difference (set 62= 59 or 61 : the total number of hits in PubMed is similar)

It obviously is a mistake of OVID MEDLINE and I will inform them.

For the meanwhile, take care to add the individual substance names when you search for drug terms that have a pharmacological action-equivalent in PubMed. The substance names are not automatically searched when exploding the MeSH-term in OVID MEDLINE.

When I search extensively for systematic reviews I prefer OVID MEDLINE to PubMed for several reasons. Among them, it is easier to build a systematic search in OVID, the search history has a more structured format that is easy to edit, the search features are more advanced giving you more control over the search and translation of the a search to OVID EMBASE, PSYCHINFO and the Cochrane Library is “peanuts”, relatively speaking.

However, there are at least two things to keep in mind when searching OVID MEDLINE instead of PubMed.

As previously mentioned, I once missed a crucial RCT that was available in PubMed, but not yet available in OVID/MEDLINE.

A few weeks ago one of my clients said that she found 3 important papers with a simple PubMed search that were not retrieved by my exhaustive OVID MEDLINE (Doh!).All articles were recent ones [Epub ahead of print, PubMed – as supplied by publisher]. I checked that these articles were indeed not yet included in OVID MEDLINE, and they weren’t.

As said, PubMed doesn’t have all search features of OVID MEDLINE and I felt a certain reluctance to make a completely new exhaustive search in PubMed. I would probably retrieve many irrelevant papers which I had tried to avoid by searching OVID*. I therefore decided to roughly translate the OVID search using textwords only (the missed articles had no MESH attached). It was a matter of copy-pasting the single textwords from the OVID MEDLINE search (and omitting adjacency operators) and adding the command [tiab], which means that terms are searched as textwords (in title and abstract) in PubMed (#2, only part of the long search string is shown).

To see whether all articles missed in OVID were in the non-MEDLINE set, I added the command: NOT MEDLINE[sb] (#3). Of the 332 records (#2), 28 belonged to the non-MEDLINE subset. All 3 relevant articles, not found in OVID MEDLINE, were in this set.

In total, there were 15 unique records not present in the OVID MEDLINE and EMBASE search. This additional search in PubMed was certainly worth the effort as it yielded more than 3 new relevant papers. (Apparently there was a boom in relevant papers on the topic, recently)

In conclusion, when doing an exhaustive search in OVID MEDLINE it is worth doing an additional search in PubMed to find the non-MEDLINE papers.Regularly these are very relevant papers that you wouldn’t like to have missed.Dependent on your aim you can suffice with a simpler, broader search for only textwords and limit by using NOT MEDLINE[sb].**

From now on, I will always include this PubMed step in my exhaustive searches.

2. OVID MEDLINE contains duplicate records

I use Reference Manager to deduplicate the records retrieved from all databases and I share the final database with my client. I keep track of the number of hits in each database and of the number of duplicates to facilitate the reporting of the search procedure later on (using the PRISM flowchart, see above). During this procedure, I noticed that I always got LESS records in Reference Manager when I imported records from OVID MEDLINE, but not when I imported records from the other databases. Thus it appears that OVID MEDLINE contains duplicate records.

For me it was just a fact that there were duplicate records in OVID MEDLINE. But others were surprised to hear this.

Where everyone just wrote down the number of total number hits in OVID MEDLINE, I always used the number of hits after deduplication in Reference Manager. But this is a quite a detour and not easy to explain in the PRISM-flowchart.

I wondered whether this deduplication could be done in OVID MEDLINE directly. I knew you cold deduplicate a multifile search, but would it also be possible to deduplicate a set from one database only? According to OVID help there should be a button somewhere, but I couldn’t find it (curious if you can).

Although the manual only talked about “multifile searches”, I tried the comment (..dedup 34) on the final search set (34) in OVID MEDLINE, and voilà, 21 duplicates were found (exactly the same number as removed by Reference manager)

The duplicates had the same PubMed ID (PMID, the .an. command in OVID), and were identical or almost identical.

Differences that I noticed were minimal changes in the MeSH (i.e. one or more MeSH and/or subheadings changed) and changes in journal format (abbreviation used instead of full title).

Why are these duplicates present in OVID MEDLINE and not in PubMed?

These are the details of the PMID 20846254 in OVID (2 records) and in PubMed (1 record)

The Electronic Date of Publication (PHST) was September 16th 2010. 2 days later the record was included in PubMed , but MeSH were added 3 months later ((MHDA: 2011/02/12). Around this date records are also entered in OVID MEDLINE. The only difference between the 2 records in OVID MEDLINE is that one record appears to be revised at 2011-10-13, whereas the other is not.

The duplicate records of 18231698 have again the same creation date (20080527) and entry date (20081203), but one is revised 2110-20-09 and updated 2010-12-14, while the other is revised 2011-08-18 and updated 2011-08-19 (thus almost one year later).

Possibly PubMed changes some records, instantaneously replacing the old ones, but OVID only includes the new PubMed records during MEDLINE-updates and doesn’t delete the old version.

Anyway, wouldn’t it be a good thing if OVID deduplicated its MEDLINE records on a daily basis or would replace the old ones when loading new records from MEDLINE?

In the meantime, I would recommend to apply the deduplicate command yourself to get the exact number of unique records retrieved by your search in OVID MEDLINE.

*mostly because PubMed doesn’t have an adjacency-operator.
** Of course, only if you have already an extensive OVID MEDLINE search.

I gather that the new changes to the OVIDSP interface are the reason why two older OVID posts are the recent number 2 and 3 hits on my blog. My guess is that people are looking for some specific information on OVID’s interface changes that they can’t easily access otherwise.

But this post won’t address the technical changes. I will write about this later.

I just want to mention a few changes to the OVIDSP databases MEDLINE and EMBASE, some of them temporary, that could have been easily missed.

[1] First, somewhere in August, OVID MEDLINE contained only indexed PubMed articles. I know that OVID MEDLINE misses some papers PubMed already has -namely the “as supplied by publisher” subset-, but this time the difference was dramatic: “in data review” and “in process” papers weren’t found as well. I almost panicked, because if I missed that much in OVID MEDLINE, I would have to search PubMed as well, and adapt the search strategy…. and, since I already lost hours because of OVID’s extreme slowness at that time, I wasn’t looking forward to this.

According to an OVID-representative this change was not new, but was already there since (many) months. Had I been blind? I checked the printed search results of a search I performed in June. It was clear that the newer update found less records, meaning that some records were missed in the current (August) update. Furthermore the old Reference Manager database contained non-indexed records. So no problems then.

But to make a long story short. Don’t worry: this change disappeared as quickly as it came.
I would have doubted my own eyes, if my colleague hadn’t seen it too.

If you have done a MEDLINE OVID search in the second half of August you might like to check the results.

[2] Simultaneously there was another change. A change that is still there.

Did you know that OVID EMBASE contains MEDLINE records as well? I knew that you could search EMBASE.com for MEDLINE and EMBASE records using the “highly praised EMTREE“, but not that OVID EMBASE recently added these records too.

They are automatic found by the text-word searches and by the EMTREE already includes all of MeSH.

Should I be happy that I get these records for free?

No, I am not.

I always start with a MEDLINE search, which is optimized for MEDLINE (with regard to the MeSH).

Since indexing by EMTREE is deep, I usually have (much) more noise (irrelevant hits) in EMBASE.

I do not want to have an extra number of MEDLINE-records in an uncontrolled way.

I can imagine though, that it would be worthwhile in case of a quick search in EMBASE alone: that could save time.
In my case, doing extensive searches for systematic reviews I want to be in control. I also want to show the number of articles from MEDLINE and the number of extra hits from EMBASE.

(Later I realized that a figure shown by the OVID representative wasn’t fair: they showed the hits obtained when searching EMBASE, MEDLINE and other databases in Venn diagrams: MEDLINE offered little extra beyond EMBASE, which is self-evident, considering that EMBASE includes almost all MEDLINE records.- But I only learned this later.)

It is no problem if you want to include these MEDLINE records, but it is easy to exclude them.

You can limit for MEDLINE or EMBASE records.

Suppose your last search set is 26.

Click Limits > Additional Limits > EMBASE (or MEDLINE)

Alternatively type: limit 26 to embase (resp limit 26 to medline) Added together they make 100%

If only they would have told us….

3. EMBASE OVID now also adds conference abstracts.

A good thing if you do an exhaustive search and want to include unpublished material as well (50% of the conference abstracts don’t get published).

You can still exclude them if you like (see publication types to the right)

Here is what is written at EMBASE.com

Embase now contains almost 800 conferences and more than 260,000 conference abstracts, primarily from journals and journal supplements published in 2009 and 2010. Currently, conference abstracts are being added to Embase at the rate of 1,000 records per working day, each indexed with Emtree.
Conference information is not available from PubMed, and is significantly greater than BIOSIS conference coverage. (…)

4. And did you know that OVID has eliminated StopWords from MEDLINE and EMBASE? Since a few years you can now search for words or phrases like is there hope.tw. Which is a very good thing, because it broadens the possibility to search for certain word strings. However, it isn’t generally known.

OVID changed it after complaints by many, including me and a few Cochrane colleagues. I thought I had written a post on it before, but I apparently I haven’t ;).

The following changes have now been implemented: (Note that I avoid the word ‘enhancements’, because I’ developed an allergy against the recent abuse of this term, although in this particular case “enhancement” may be justified)

Results Manager is collapsible and available above and below the main search box

Ability to move the Search History above the main search box, sort searches in ascending or descending order, and identify each search by search type

Customize common limits on the main search page

Ability to create, edit, and add multiple annotations to a citation

Browse Books and Browse Journals links are now on the Select a Database page

Browser support for adjusting font size

When logged into their personal accounts, users will see their name and institution.

To begin with the last point, I was unpleasantly surprised that I had to fill in a whole list of details (name, address, institution) when I assessed one of my saved searches. With the emphasis on one. I’ve literally a few dozens of accounts, at least one for each patron. Should I fill in the patron’s name or mine?…each time? Dee (on twitter) said she just filled in 0 in most boxes. You can also press the back button.
OVID apparently requires this personally identifiable information for My Projects so you can create a community to collaborate with others later on.

But what an improvements! 🙂 This is really what I had hoped for (see this post on the new OVID SP; and a previous one about Ovid causing RSI). ‘All’ boxes collapsible, and movable… Although I first didn’t succeed in moving the Search History, but via the OVID-SP-screenshots I found out that it was just a little grey square you had to press (with a pop-up if you move your mouse over it, see figure above). No more endless scrolling, no more pain in my wrists after a whole day searching. Almost, almost ideal… If..If …the Search Tip wasn’t so prominent. 😦 As I said before, the Tip (that never gave me any useful information) fills 1/3 of the search screen. Because of this, the unnecessary addition of the field “Search Type” and the broad columns, the search history itself comprises less than 1/4th of the screen. Thus it is difficult to keep a good overview over large searches (see for instance the screenshot and the video below )

Compare the “usual view”

with the search in “print” format

And see the original search in this ultrashort video:

I’m not the only one that dislikes the Tipbox. According to a recently finished survey on the original OvidSP-version redesign earlier this year the number one thing people wanted to change was to remove or hide the Ovid Tips (see PDF of Danielle Worster’s and Debbie Pledge’s poster here). Overall one of the main concerns was the usage of screen space by the new design including features- including the Tips on the right hand side and the new placement of Results Manager.

With Danielle I wonder how the recent changes will be perceived. Will the people who complained about the new interface be pleased with the new arrangements? And what about the people that just thought it was fine? And those who’s main frustration was the adaptation to the new interface? One librarian sighed at the MEDLIB-list: “what is the credibitiy of the library in promoting the 3rd Ovid advanced search version in less than a year over the relatively consistent PubMed interface?” It is interesting how perceptions can differ. Personally I find it much harder to explain why functionalities (like ATM!) change radically while the interface looks the same (and are therefore not noticed).

Isn’t it most important that adaptations represent (1) improvements, (2) preferably easy to understand? Of course there is a limit to the number of substantial changes and their frequency. We know that the second update of OvidSP version 2 lies ahead and I sure wish that it will be soon followed by a third one that brings us an optional TIP-box. I don’t hope that the suggestion raised at Danielle’s blog, that “the Tip-box was created for advertising (commercials?) to recover the cost of all these (unnecessary) changes” is true.More basic changes concerning Reference Manager as discussed by Krafty are also welcomed, at least by me.

“Some last minute adjustments are being carried out at present to ensure the absolute excellence of the platform. Unfortunately this means that the release date has been postponed with no new date available yet.”

Thus we have to wait a few days for the much-desired new OvidSP version.
That’s regretful, because my coming days are fully planned with OVID searches and I’m really looking forward to this new flexible platform…. But changes are on their way… And I’m looking forward to them

Transforming the Way You Search with More Flexibility and Customization of OvidSP Workflow Tools

Dear Ovid Customer:

The next release of OvidSP on July 31st is all about flexibility and enabling users to search the way they want to search. In our third weekly email introducing what you and your users will see on July 31st, learn more about new user-configurable customization enhancements to OvidSP’s workflow tools that further deepen the search experience and help users get to the results they need quickly.

Search Aid – Now users can expand or collapse this search refinement featurebased on their preferences for managing the results screen.

Search History– Many users perform complex searches, some involving as many as 60-80 lines of search. Now, the Search History can be placed above or below the main search box, so there’s no need to spend time scrolling up the page to review search strategies. Plus, you can sort all your searches in either ascending or descending order so that the last search statement is always viewable.

Results Manager – To accommodate for a wide variety of user behavior and to minimize scrolling when it comes to managing results, the Results Manager is now located in two places, above and below the results set. You can minimize it in both places to save valuable screen real estate.

Plus, now you can customize the “common” limits—those available on the main search page. These settings will act as defaults for users who are able to login via a personal account.

Like all of the upcoming enhancements and new features, those illustrated above are based on extensive feedback from and interviews with customers and users.

Coming soon to the OvidSP Resource Center will be screenshots, an updated training schedule, Frequently Asked Questions, and more. Be sure to contact your Ovid Account Representative or support@ovid.com with any questions.